(1) Field of the Invention
The present invention relates to a beer container, such as a can or bottle, utilized for direct drinking of the content, i.e., the beer being drunk directly from the container without being transferred to a receptacle such as a mug. More specifically, it relates to such a container having means for frothing the content thereof just before drinking same.
(2) Description of the Related Arts
It is well known that it is preferable to form a creamy layer of microfroth on the surface of beer just before drinking the beer, as such a layer improves the taste of the beer. Generally speaking, when beer is forcibly poured into a mug from a large size barrel, having a content of, for example, 25 liters or 10 liters, by utilizing a high pressure gas, such as carbonic acid gas, a layer of froth having a good body is formed on the surface of the beer. This layer is formed because carbon dioxide dissolved in a saturated state in the beer accommodated in the barrel, under a high pressure of 2 to 3 kg/cm.sup.2, is rapidly gasified by the mechanical impetus imparted on the outflowing beer stream. Contrary to this, in the case of a medium size can suitable for home use or personal use made from a metal or plastic and having a content of, for example, 2 or 3 liters, the beer contained therein is usually completely consumed without necessity to consider restoring a residual content therefore, since a high pressure gas is not necessarily used when pouring the beer out of the container, gasification of the supersaturated carbon dioxide becomes relatively poor.
Many proposals have been made for forming a micro-froth layer on the surface of beer accommodated in a medium size container prior to drinking. For example, in Japanese Unexamined Patent Publication (kokai) No. 56-74487, a means is provided for facilitating the gasification of carbon dioxide dissolved in the beer by pouring the beer from a container into a mug through a tap having a main supply opening and at least an auxiliary opening, whereby the beer stream poured from the auxiliary opening taps upon the surface of the poured beer in the mug, which generates vibration and forms a flock of micro-froth on the surface of the beer in a mug. The froth flock is moved to and fro by a beer stream poured from the main supply opening and form a creamy layer on the entire surface of the beer.
In Japanese Unexamined Patent Publication (Kokai) No. 57-28797, a means is proposed for forming a froth layer, comprising a tap for a container having an air inlet pipe designed to have a proper inner diameter and length so as to impart a pulsative movement to an outflowing stream of beer.
The above-mentioned means, however, are effective only for a relatively large size container from which the beer therein is poured into a mug for drinking. Accordingly, these prior arts are not suitable for the purpose of the present invention, in which the beer is drunk directly from the container after a lid thereof has been opened.